Fluid flow control apparatus



Jan. 14, 1969 w, BAlNs 3,421,324

FLUID FLOW CONTROL APPARATUS Filed May 3, 1966 I N VEN TOR. W/Zl lAM R.BAH/VI AGfA/f United States Patent 3,421,324 FLUID FLOW CONTROLAPPARATUS William R. Bains, Tustin, Califi, assignor to Phiico-FordCorporation, a corporation of Delaware Filed May 3, 1966, Ser. No.547,306 US. Cl. 60-231 Int. Cl. F021: 1/14; F152 ]/08; 1305b 7/08 3Claims ABSTRACT OF THE DISCLOSURE This invention relates to apparatusfor controlling fluid flow, and more particularly to improved apparatusfor controlling the direction of flow of a stream of gas as it isdischarged from the nozzle of a reaction motor. While of broaderapplicability, the invention has particular utility in the field ofguidance systems for missiles or rockets.

One known system for propelling a missile by use of a gas stream issuingfrom a nozzle utilizes an auxiliary gas stream to control the directionof thrust of the propelling stream, whereby to steer the missile. Insuch apparatus, the issuing gas stream may be deflected from oneposition to the other by means of jets as gas released from a suitableauxiliary source and directed transversely of the main gas stream in thethroat section of the reaction motor. The auxiliary source, in a typicalprior arrangement, may comprise a container of gas under pressure. Gasis released from the container through electromechanical valves, asdirected by the missiles guidance control system, thereby to deflect thepath of the issuing gas stream and steer the missile.

It is a general objective of the present invention to provide improvedauxiliary gas supply means of the abovementioned type for controllingdeflection of the propelling stream, which means overcomes the need formaintaining a supply of control gas under pressure.

It is a further objective of the invention to provide improved auxiliarygas supply means that is both positive acting and rapid in achievingcontrol of a main gas stream.

It is a still further objective of the invention to provide improvedguidance control means which minimizes the use of moving parts and ishighly reliable in operation.

To these general ends the invention contemplates, in a preferredembodiment thereof, the use of at least a pair of oppositely disposedcontrol ports extending transversely of and into gas flow communicationwith the constricted neck portion of the missile nozzle, means definingat least a pair of chambers each in gas flow communication with acorresponding one of the control ports, and a plurality of combustible,gas generating charges disposed within each of the chambers. Means isprovided for igniting the charges in accordance with a desired sequencerequired to guide the missile, ignition of a charge establishinginstantaneous flow of a jet of gas through a corresponding one of thecontrol ports. The jet is operable to deflect the stream of propellantgas flowing through the nozzle, and the vehicle is steered accordingly.

Advantageously, the invention overcomes the need for storing control gasunder pressure, as well as the electromechanical valves usuallyassociated with means for storlng gas.

The manner in which the foregoing as well as other objectives andadvantages of the invention may best be achieved will be understood froma consideration of the following description, taken in light of theaccompanying drawing in which:

FIGURE 1 is an elevational showing, partly in section, of apparatusembodying a preferred form of the invention, with some parts broken awayand other parts shown diagrammatically;

FIGURE 2 is a sectional view taken along the line indicated by arrows 22applied to FIGURE 1, and illustratingd additional constructionalfeatures of the invention; an

FIGURE 3 is a sectional view taken along the line indicated by arrows3-3 applied to FIGURE 1.

With more particular reference to the drawing, and first to FIGURE 1, amissile or rocket 5 is constructed and arranged to be propelled by astream of gas caused to flow through a convergent-divergent nozzle 10having symmetry about a central axis common to both the nozzle and themissile. Preferably the nozzle 10 includes a generally conical flowdivider 11, and divergent Walls 12 cooperably disposed with respect toflow divider 11 to form an annular outflow port, as is best seen inFIGURE 3. Flow divider 11 conveniently is supported by brackets 18 sodimensioned and spaced as not appreciably to obstruct the annularoutflow port.

With reference also to FIGURE 2, first and second pairs of control ports13 and 14 interconnect pairs of chambers 15 and 16, respectively, withopposite sides of a restrictive portion 17 of the nozzle 10. Chambers 15and 16 include respective tapered portions 15a and 16a leading up toports 13 and 14. These tapered portions serve to enhance flow of controlgas through the control ports, as will be appreciated from furtherconsideration of apparatus embodying the invention.

Supply of a main propellant gas stream to nozzle 10 is provided by knownmeans, such as a propellant gas generator designated generally by thenumeral 6, and connected to a nozzle inlet port 19 communicating withconvergent nozzle portion 21 disposed upstream with respect torestrictive portion 17.

In particular accordance with the invention, arrays or groups ofcombustible, gas generating charges, such for example as squibs 22, aredisposed in each of chambers 15 and 16, preferably on side walls of thechambers opposite the ports 13 and 14 communicating with narrow neckportion 17 of nozzle 10. Apparatus for igniting squibs 22 comprisesindividual control circuits 23 that extend through walls of chambers 15and 16 and are connected, through cable portions thereof, to guidancecontrol means associated with the missile and designated generally bythe numeral 24. A sufficient number of squibs 22 is provided so thatcontrol may take place for the duration of energization of the gasgenerator 6 with which the nozzle is associated.

Each of squibs 22 comprises a self-contained gas generator energizableby propellant of suitable composition, a number of which are known inthe art. Ignition of the propellant also may be accomplished by suitableknown bridge wire circuit means associated with control circuits 23. Itof course will 'be understood that selection of the squib propellantwill be such as to ensure compatibility of gases generated by a squib 22and by the generator 6. Moreover, the construction and disposition ofthe squibs is such that firing of a squib in a chamber 15 will notadversely affect any other squib in that chamber.

Objectives and advantages of the invention will be more fully understoodfrom a consideration of operation of the apparatus thus far described.Assuming first that energization of the gas generator 6 will cause astream of propellant gas to issue from nozzle 10 in substantially equalquantities about flow divider 11, the missile will be steered on asubstantially straight course. To effect a change of course, a signal isgenerated by control 24 igniting a squib 22 in chamber to create a gaspressure wave that moves with substantial force. The art provides anumber of ways in which the control signal may be generated. Howeverthese will not be described herein since the invention is directedessentially to the novel squib and control port combination forcontrolling gas flow through a nozzle, as set forth in the appendedclaims. If detailed description of suitable means is desired, referencemay be had, by Way of example, to the copending application of Louis G.Walters et al., bearing Ser. No. 371,715 and assigned to the assignee ofthe present invention.

The pressure wave created by the burning squib is transformed into acontrol jet of relatively hot gas as it moves from chamber 15, throughtapered portion 15a, and through the port 13 communicating with therestrictive section 17 of nozzle 10. The control jet in moving from port13 will impinge upon the issuing gas flow stream and deflect it, e.g. tothe right, causing the stream to flow to the right of flow divider 11 asshown in FIGURE 1. The course of the missile is changed accordingly.

Once the force of the control jet has been dissipated, the main gas flowstream 25 will remain in the described deflected position due to theso-called Coanda effect, as is characteristic of apparatus of the typedisclosed. In general, the Coanda effect is the tendency of a stream offluid flowing close to a surface to be deflected toward the surface,and, under proper conditions, to flow tangentially to the surface andattach thereto.

As viewed in the two-dimensional showing of FIGURE 1, the flow of gasthrough nozzle 10 is stable in at least two states, and is thereforetermed bistable. Since stability is achieved in at least two states, theissuing gas stream can be switched from the right side of the nozzle tothe left side by igniting a squib to induce flow of a control jetthrough the control port that is nearer the displaced portion of the gasstream flowing through the restrictive nozzle portion 17. Since theissuing stream is maintained stable in its displaced position because ofthe Coanda effect, the control gas jet need only flow until deflectionis achieved. Flow of a control jet from another direction, i.e. from oneof the other control ports illustrated, must be initiated to switch theissuing stream to another position.

While operation of apparatus embodying the invention has been describedin terms of a two-dimensional, bistable device, it will be understoodthat the illustrated apparatus is three-dimensional in construction,affording control in a plane perpendicular to the plane of FIGURE 1.This constructional feature is fully illustrated in FIGURE 2, where bothsuch planes of control are illustrated.

It will be appreciated that steering is achieved in the disclosed nozzle10 by alternate ignition of appropriately positioned squibs 22 under thecontrol of means 24, and that a suflicient number of squibs will beprovided in each chamber to achieve control for the duration of gas flowthrough the nozzle.

From the foregoing description it will be appreciated that the inventionaffords improved auxiliary gas supply means for controlling deflectionof a gas stream issuing from a nozzle, which means overcomes the needfor maintaining a supply of control gas under pressure. Moreover, thedisclosed gas supply means is both positive acting and rapid inachieving control of the main gas stream. These characteristics adaptthe apparatus of the invention to particular use in the guidance controlmeans for a missile propelled by a reaction motor.

I claim:

1. Fluid flow control means comprising: nozzle means having aconstricted throat section and a divergent exhaust portion through whicha stream of gas may flow; at least a pair of spaced control portspositioned to direct jets of gas transversely of the stream of gascaused to flow through said nozzle means; means defining a pair ofseparate chambers, each chamber communicating with one of said ports; atleast a pair of groups of individual, selectively energizable gasgenerating charges, the group of each said pair being disposed within acorresponding one of said chambers; and means for energizing saidcharges individually, in accordance with a desired sequencecharacterized by the energization of one charge of one group then onecharge of the other group, the construction and arrangement being suchthat energization of a single charge is operable to create rapid flow ofgas through a corresponding one of said control ports and to deflect thestream of gas flowing through said nozzle, such deflected streamthereafter flowing in adjacency to a surface of a divergent portion ofsaid nozzle until another charge is fired and gas is caused to flowthrough the other control port.

2. Control means according to claim 1 and characterized in that ports ofsaid pair are disposed opposite one another.

3. Fluid flow control means for guiding a vehicle propelled by a highvelocity stream of gas flowing through nozzle means having a constrictedneck portion and a wall portion divergent therefrom to form the exhaustfor the flowing gas, said control means comprising: at least a pair ofspaced control ports arranged to direct a jet of gas transversely of therecited stream of gas caused to flow through the constricted neckportion; a plurality of combustible, gas generating charges compris inga pair of groups each disposed to effect the recited flow of gas througha corresponding control port; and means for igniting said charges inaccordance with a vehicle guiding sequence characterized by ignition ofcharges of alternate groups, ignition of a single charge of one groupbeing operable to establish the recited flow of a jet of gas through acorresponding one of said control ports and to deflect the stream of gasflowing through said nozzle to a position in which it is thereaftercaused to flow adjacent a surface of the divergent Wall portion until agenerating charge of another group is ignited to deflect the stream ofgas for flow adjacent another surface of the divergent wall portion.

References Cited UNITED STATES PATENTS 2,956,401 10/1960 Kane 60-2503,066,489 12/1962 Kirshner et al. 60-3947 X 3,143,853 8/1964 Sobey 60256X 3,204,405 9/1965 Warren et al. 6023l 3,228,188 1/1966 Sargent et al.60231 3,273,801 9/1966 Wilhite 60-231 X 3,279,185 10/1966 Lewis et al60-231 3,285,262 11/1966 Ernst et al. 60231 X 3,300,978 1/1967Pennington 60-231 CARLTON R. CROYLE, Primary Examiner.

US. Cl. X.R.

